Extent of shielding by counterions determines the bactericidal activity of N,N,N-trimethyl chitosan salts

Author(s)

Follmann, Heveline D. M. ^{[1, 2]} ; Martins, Alessandro F. ^{[2, 3]} ; Nobre, Thatyane M. ^[1] ; Bresolin, Joana D. ^[4] ; Cellet, Thelma S. P. ^[2] ; Valderrama, Patricia ^[5] ; Correa, Daniel S. ^[4] ; Muniz, Edvani C. ^{[2, 6]} ; Oliveira, Jr., Osvaldo N. ^[1]

Affiliation

^[1] Univ Sao Paulo, Sao Carlos Inst Phys, BR-13566590 Sao Paulo - Brazil

^[2] State Univ Maringa UEM, Dept Chem, GMPC, BR-87020900 Maringa, Parana - Brazil

^[3] Technol Univ Parana UTFPR, BR-86812460 Apucarana, Parana - Brazil

^[4] Embrapa Instrumentat, BR-13560970 Sao Paulo - Brazil

^[5] Technol Fed Univ Parana UTFPR, BR-87301899 Campo Mourao, Parana - Brazil

^[6] Paranaense Univ UNIPAR, Grad Program Biotechnol Appl Agr, BR-87502210 Umuarama, Parana - Brazil

• Document type: Journal article
• Source: Carbohydrate Polymers; v. 137, p. 418-425, FEB 10 2016.
• Web of Science Citations: 14

Abstract

In this study, we show that the bactericidal activity of quaternized chitosans (TMCs) with sulfate, acetate, and halide counterions against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) correlates with the ``availability{''} of N-quaternized groups {[}-N+(CH3)(3)] in the TMCs backbones. N,N,N-trimethyl chitosan sulfate (TMCS) and N,N,N-trimethyl chitosan acetate (TMCAc) displayed the highest activities, probably due to their delocalized pi system. Among TMCs with halide counterions, activity was higher for N,N,N-trimethyl chitosan chloride (TMCCl), whereas N,N,N-trimethyl chitosan iodide (TMCI) and N,N,N-trimethyl chitosan bromide (TMCBr) exhibited lower, similar values to each other. This is consistent with the shielding of -N+(CH3)(3) groups inferred from chemical shifts for halide counterions in (HNMR)-H-1 spectra. We also demonstrate that TMCs with distinct bactericidal activities can be classified according to their vibrational spectra using principal component analysis. Taken together, these physicochemical characterization approaches represent a predictive tool for the bactericidal activity of chitosan derivatives. (C) 2015 Elsevier Ltd. All rights reserved. (AU)

• FAPESP's process: 14/03511-9 - Nanostructured films of (lactated-TMC)/(CS) obtained with distinct LbL deposition methods
• Grantee: Heveline Dal Magro Follmann
• Support Opportunities: Scholarships in Brazil - Post-Doctoral